• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.240-246
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• 1999

The determination of surface topography is believed to be extremely important in the areas of contact mechanics, adhesion and friction. In order to describe topography of various frictional surface, the wear test was carried out under different experimental conditions in dry friction. And fractal descriptors was applied to frictional surface of laser modified steel with image processing system. These descriptors to analyze surface structure are fractal dimension. Surface fractal dimension can be determined by sum of intensity difference of surface pixel. Topography of frictional surface can be effectively obtained by fractal dimensions.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.174.2-174.2
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• 2005

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.1904-1911
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• 2003

In order to determine the wear properties of AIP (Arc Ion Plating) deposition, wear process was evaluated by using a Falex test machine. Also, in order to determine the effects of coating material on the wear process, TiC, TiN, and TiCN coatings of thickness about 5 $\mu\textrm{m}$∼6 $\mu\textrm{m}$ coated by Arc ion plating deposition method were tested. The wear property was determined under a dry sliding condition as a function of the applied load, sliding distance, sliding velocity and temperature. The results show that when wear of the coating-layer occurred, specific wear amount increased with the wear rate. At initial state, the wear rate rapidly increased, but it gradually reduced as the velocity increased. Also, when raising the temperature, the wear rate increased in the order of TiCN, TiN and TiC due to the frictional heat.

• Tribology and Lubricants
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• v.12 no.1
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• pp.22-28
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• 1996

This study was undertaken to investigate the dry wear characteristics and mechanism of KP-4M steel for plastic molding against SKD 61 hardened by heat treatment. The wear test was carried out under different conditions such as sliding speed, contact pressure, sliding distance, with frictional tester of pin on disc type. The wear loss on variation of sliding speed was little in lower speed range below 0.5 m/sec and in higher speed range above 1.5 m/sec,'but wear loss was high in intermediate speed range. The critical sliding speed, which showed the maximum value of specific wear rate, became lower with increased contact pressure. Increasing the contact pressure, the critical sliding distance Lcr which the wear mechanism changes from severe wear to mild wear was increased due to the decrease of oxidation reaction velocity. Through this study we suggested a model of generation and elimination process of wear debris of KP-4M steel for plastic molding.

• Tribology and Lubricants
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• v.21 no.2
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• pp.93-99
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• 2005

The fault of an automobile transmission gear occurs whenever moving tooth surfaces interact. Such a failure condition has an effect on the frictional factors such as applied load, sliding speed, frictional time and gear oil. However, it is difficult to know the mutual relation of these factors. In this study, the friction and wear tests were carried out to get the friction characteristics with carburized SCM420 and nitrocarburized NT100 have being used as automobile transmission gear materials. And it was undertaken to analyze the frictional factors that have effect on frictional characteristics by using design of experiment. From this study, the result showed that the applied load in frictional factors was the most important, next to frictional time, sliding speed. And the friction characteristics of nitrocarburized NT100 was more excellent than carburized SCM420.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.03a
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• pp.78-89
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• 1995

Phenomelocial evidences for three-dimensional crystallizing $\pi$-bondings are investigated in case of the soft layer very near the suface of the metal , the surface layer of certain crystaline thermoplastics. the increased contact area of the metalic frictional interface and the delaminated sheet-like wear particles of the metal . The wear mechanisms are the cracks at the boundaries of the grains and their propagations parallel to the surface. The cracks are made by the reorientations of the atoms in the grains and the rotations of the grains.

• Tribology and Lubricants
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• v.15 no.4
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• pp.291-296
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• 1999

This paper presents the results of thermoelastic wear behaviors in ventilated disk brakes for a high-speed automotive and train using the finite element method. The computed results show that the sinusoidal distortions due to non-uniform distributions of temperature profiles may lead to thermoelastic wears on the rubbing surface. This may decrease the service life of a disk brake and produce micro-cracks, noise and squeals between two rubbing surfaces.

• Tribology and Lubricants
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• v.6 no.1
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• pp.108-115
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• 1990

Wear diagrams, which are the three dimensional representations of the dependence of the wear rate on the applied pressure and the sliding speed, were constructed with the pin on ring type wear test results using 52100 wear couples. The pressure and speed ranges from 0.45 MPa to 45.30 MPa and from 0.012 m/sec to 0.12 (0.120)m/sec, respectively. The results show the mild to severe transition, which suggests the change of the wear mechanisms as a function of the pressure and sliding speed. The SEM micrographs of the corresponding worn area shows clearly that different wear mechanisms dominate.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.199-205
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• 2002

This paper presents a numerical technique to analyze wear life of automotive disk brake pad, where FFT-FEM method is adopted to determine the transient temperature distribution of the disk surface. A specimen ova frictional material is tested on a small scale brake dynamometer to find the dependency of the wear rate on temperature change, from which and the temperature analysis results, given the wear test mode, wear behavior of the pad material fur the vehicle can be predicted. Numerical examples show the predicted wear life of the vehicle coincides with the manufacture's recommended time interval for replacing the pads.

• Transactions of the Society of Information Storage Systems
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• v.9 no.2
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• pp.36-41
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• 2013

Frictional behavior of a single carbon nanotube(CNT) was investigated using molecular dynamics simulation. A single CNT aligned horizontally on silver or graphene substrate was modeled to evaluate its frictional behavior such as frictional force and rolling/sliding motion with respect to potential parameter and lattice structure of the substrate. As a result, it was found that friction and rolling was affected by adhesion between two surfaces and period of the rolling depended on lattice distance of the substrate.